<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>事件绑定</title>
		<script src="js/jquery-3.3.1.min.js" type="text/javascript" charset="utf-8"></script>
	</head>
	<body>
		<input type="text" id="" value="" />
		<p>单机输入框获取焦点</p>
		<span style="display: none;">请输入你的电话</span>
	</body>
</html>
<script type="text/javascript">
	// $(document).ready(()=>{
	// 	$("input").bind("focus",()=>{
	// 		$("span").show()
	// 	})
	// })
	$(document).ready(()=>{
		$("input").focus(()=>{
			$("span").show()
		})
	})
</script>